Method of threading pearls, corals, and the like



June 19, 1951 v. ADAM METHOD OF 'I'HREADING PEARLS, CORALS, AND 'IjHE LIKE Filed m. 26. 1949 INVENTOR wu- M ATTORNEYS Patented June 19, 1951 METHOD OF THREADI NG PEARLS, CORALS, AND THE LIKE Vaclav Adam, Jablonec Nad Nisou, Czechoslovakia, assignor to 'Ceskoslovenske zavody sklarske, narodni podnik, Prague, Czechoslovakia Application January 26, 1949, Serial No. 72,975 In Czechoslovakia January 29, 1948 l-(llaim. 1

This invention relates to an improved method of threading pearls, corals and the like. Up to the present time, pearls and corals are threaded on the thread in the following simple way: fin steel needles are inserted several times in a container filled with pearls or corals until a certain number of pearls or corals are engaged on them; the pearls or corals are counted on and they are made to slide from the needles to the thread. This method is impractical, because it is necessary to classify previously the pearls or corals in order to exclude such of themes have smaller openings than the diameter of the needle. If the previous classifying has not been executed carefully enough, there arises the following defect: the pearls or corals with openings with smaller diameters than the diameter of the needle are picked on the point of the needle and do not slide further on it. This fact causes the needle to be put out of work. Therefore the output of apparatus of this kind is very low and the upkeep is very expensive, because the needles must be manufactured of materials of the best quality for they are exposed to an excessive abrasive action. Up to the present day, pearls and corals of small sizes are threaded only by hand.

The method of threading pearls, corals and the like according to this invention removes all the mentioned disadvantages and an apparatus for performing the method permits a greater output than the previous equipments offer, especially, if the apparatus to perform the method are arranged in banks. The method permits an exact counting off of the pearls and puts the thread automatically and simultaneously through all pearls.

In order that the principles of the present invention may be better understood there is attached a drawing in which the single figure is a semi-diagrammatic vertical section of an apparatu embodying the invention. In the'drawing l represents a funnel in which an approximately measured quantity of pearls or corals is poured. The pearls or corals slide into the bore of a vertical rotatably mounted rubber tube 2 through the lower opening of the funnel I. The rubber tube 2 is provided with a, similar funnel 4 on its upper end. A tube 3 acting as an adjustable stop is inserted into the lower end of the rubber tube 2. The quantity of pearls or corals which are to be threaded, can be regulated with the help of the stop tube 3. This stop tube 3 may be connected with a vacuumpump by means of which the thread is put through a connected channel produced by putting in order the pearls or corals with the passages thereof in alinement. The rubber tube 2 communicating with the funnel 4 is supported in a bearing on any place of the tube 2 or of the funnel 4. Round the funnel 4 there is an annular body 5 in order to catch excess pearls or corals which are discharged at starting rotation of the tube 2 and of the funnel 4 respectively. The discharged pearls or corals are delivered from the body 5 to the magazine through an inclined outfall 5.

Pearls or corals are threaded-according to this inventionin the following way: an approximately measured quantity of pearls, corals etc. of any desired size is poured into the funnel I which has its lower opening in the neighbourhood of the upper opening of the tube 2 at that place where the tube 2 changes into the funnel 4. The said pearls or corals slide into the tube 2 where they accumulate above the stop '3. Axes of the openings of the pearls or corals are still in divers directions. Any excess of pearls or corals escapes from the funnel 4 into the body 5 after starting rotation due to the rotational force and is delivered therefrom back into the magazine. Each of the pearls or of the corals in the bore of the tube 2 is subjected to centrifugal force after startin rotation of the tube 2. This force is the greater, the heavier the material of the pearls or corals and the greater their diameter. The necessary minimal number of revolutions to be given the tube 2 depends on the mentioned circumstances and it can be ascertained by experience for any kind of pearls or corals. The rotation of the filled tube 2 is executed during some seconds and after stopping it the pearls or corals which will then be oriented with the passages therein in vertical alignment are fixed in this position by stretching the rubber tube 2 in the direction of its longitudinal axis which causes diminishing of the diameter of the tube 2 and produces a firm holding of the pearls or corals in the tube 2. Thereafter the evacuation-pump is brought into operation and the thread is led into the connected channel produced by the aligned channels of the fixed pearls or corals. It is evident that the suction may be replaced also by overpressure exercising influence on that end of the thread which is to be put into the pearls or corals. An end of the thread-preferably the upper end-is made sure in any way e. g. by gluin it with wax, by making a loop on the thread etc., then a stretch in the direction of the axis of the tube 2 is relieved 3 to release the grip on the contents of the tube. The as threaded product then falls into a prepared container upon removing the stop tube 3.

I claim:

The method of threading pearls or corals having a diametral bore which comprises placing the bored pearls in an elastic tube having a normal diameter such that the pearls have a loose it therein, rotating the tube and its contents about the axis of the tube at a rate sufficient to dispose the pearls in the tube with the bores thereof in alinement with each other and with the axis of the tube, deforming the tube by stretching the same in the direction of it axis whereby to grip the pearls in aligned position, passing a thread through the bores of the pearls while so gripped in the tube, releasing the ten- 4 sion on the tube and removing the threaded pearls therefrom.

VACLAV ADAM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,087,481 Roby et a1. July 20, 1937 2,322,730 Karreb June 22, 1943 FOREIGN PATENTS Number Country Date 454,732 France July 11, 1913 

